The Diet In Old Age
( Originally Published 1921 )
The average man does not concern himself with the question of how long he is to live until he begins to grow old. I, therefore, have entitled this chapter "The Diet in Old Age"; but it might better be called "the diet to prevent old age," or "the diet to increase the length of life."
There is really little distinction between the ideal diet for old age and the ideal diet for any other period of life. The ideal diet will increase the length of life, and the earlier in life it is adopted, and the more consistently it is followed, the greater will be the increase in the count of years. Too often it is only when most of life is past that we begin to value it, and hence are the more concerned with its extension, and the more keen in search of methods of eating that will prolong the years that remain.
If you will read a considerable number of accounts of the habits of living of men who have achieved the distinction of unusual years and a vigorous and hearty old age, you will find numerous reasons set down in explanation of the unusual longevity. In some instances the chief credit will be given to systems of physical exercise; in some cases, to habits of thought; in others to hours of sleep or an out-door environment; while, on the other hand, you will find the abstinence from some particular vice—or even the addiction to some vice, or the use of some drug (witness the advertisement of Duffy's Pure Malt Whiskey) set down as the cause of longevity. But in all creditable accounts of longevity you will find running through them one element of uniformity: in-variably those 'who live to unusual years have practised abstemious habits of eating. Cornaro, the Italian Paytone+One, who lived several centuries ago, attained the age of 101; when in his nineties he wrote a book on longevity, in which he ascribed his unusual age and vigor to his spare diet. He has been misquoted as saying that "he lived upon one egg a day"; this, of course, referred only to the use of the single egg in place of meat, but his diet was very simple in quality and very spare in quantity.
In 1635 a certain very old man named Thomas Parr visited King Charles. Mr. Parr informed the king that he (Parr, not the king) lived on cheese, milk, a little coarse bread and sour whey. Mr. Parr laid claim to 153 years. He may have falsified about his age, though he may have told the truth about his diet. ,
These stories of those who lived a century or more are always interesting, but they are not so convincing, at least to the scientific mind, as are the statistics of the insurance companies to which reference has been made in our chapter on obesity. The insurance people have no data of the diet of the policy-holders, but they do have records of their weights, and the relation of the weight to the quantity of food eaten is an absolute and positive one. Fat men cannot be light eaters and thin men cannot be heavy eaters, except in abnormal cases. Insurance statistics show that over-weight, and hence over-eating increases the death rate, and this increase is specially marked around the age of forty. Such increase in the death rate diminishes some-what with further advancing age, but at ' the age of sixty, the death rate for the fattest group of men was about seventy per cent greater than for the group of the slenderest men of the same age period.
We have no insurance data for men beyond this age group, as too few men are insured after that age to secure reliable statistics. But the facts we have certainly offer very convincing proof that fat men do not live as long as those of spare frame. Practical observation among the old people you know will convince you of the same fact. Fat old men are very rare, and those who are fat will usually be found to have acquired the condition late in life. Men who have been fat all their lives rarely live beyond the fifties or sixties. It is those with spare frames, and hence abstemious eaters, whom you will find still living in the eighties and nineties.
It did not seem difficult to explain these facts. We simply knew that a light eater who maintained a spare and wiry figure outlived the heavy eater whose form was burdened with fat. Obesity burdens the body and prevents proper activity; over-eating fills the body with surplus food wastes which generate poisons and overtax the excretory organs; moreover, over-eating and obesity cause, or at least, render one more susceptible to various diseases. These facts alone might seem sufficient to explain the greater longevity of the abstemious eater.
However, I believe that we have found an additional explanation in the discoveries that have recently been made concerning the general physiological effects of a light versus the heavy diet. The light eater does not live so fast, hence he lives longer. This statement is literally true, and the word "fast" is not necessarily used as a synonym for immorality. The restricted diet of Dr. Benedict's experiments resulted in an actual slowing down of the rate of the heart beat; this decrease was in fact about thirty per cent. If we assume that a man comes into this world like a wound up clock, capable of so many ticks, it seems quite logical that if he ticked fast he would not tick as long—this is an unusual viewpoint, but it may be a great truth that we are only just discovering.
We are accustomed to measuring life in years, that is, the number of times the earth goes round the sun, which has nothing in particular to do with the life processes. Measuring life in the number of heart beats would certainly be more logical. The over-eater who is fat, who pants, is short of breath, who has a high pulse rate and a high blood pressure, is physiologically running too fast, and hence will run down too quickly. The light eater who is spare of frame, who has a slow pulse rate and a low blood pressure, is living more slowly and will hence live longer. Incidentally he has more reserve power for emergencies. Sudden exertion increases the rate of the heart beat, but if it is already beating rapidly due to the burden of digesting and eliminating surplus food, then it has not as much opportunity left for increase from the legitimate stimulation of exercise. Hence the fat man, when he becomes excited and runs a block, tumbles down with heart disease or breaks a blood vessel and dies from apoplexy.
The doctor's certificate rarely sets down "old age" as the cause of death. The majority of those deaths which occur in late middle life are from diseases plainly related to incorrect living and chiefly to over-eating. It is such deaths that take off a man before his time and shorten life. The way to prevent this is to avoid the cause.
In old age the general activities of the body are decreased. Old people move more slowly and work less vigorously than the young, and, unless special pains have been made to maintain them, the bulk of the muscles materially decrease. All these facts contribute to the reduction of the amount of food needed to maintain life; hence even though the diet has been correctly proportioned in youth, as age advances it should be decreased. If over-eating has been practised in youth and middle life the need of such decrease is much greater.
The nature of the food and the quality of the diet need not be changed. There is less need of energy-producing foods, but there is also less need of other food elements as all the life processes have been checked in speed and the volume of muscles has usually been de-creased. The mineral salts, vitamines and avail-able proteins are still essential; the fat, sugars, and starches which furnish the fuel energy are also required, but in reduced quantities.
In some cases the loss of natural teeth will render mastication a little more difficult, and hence require the adoption of foods more easily masticated. Resort should not be had, however, to excess of starchy porridges, 'as there are plenty of natural foods that may be eaten without laborious chewing. The adoption of the method previously described in "eating" milk or that used in Horace Fletcher's habit of holding foods, even liquids like milk and soup, in the mouth and working them about until they are mixed with saliva and swallowed instinctively is to be recommended for those who are not able to chew hard foods:
With the wear of years, especially if wrong eating habits have been followed, the digestive powers may become somewhat weakened. The exact nature of the impairment of digestion varies with the individual, and hence cannot be met by any general rules or remedies. There are some, foods, however, that are so readily digested that they may be used by almost any one, no matter how enfeebled the digestion may be. Milk and eggs rank very high in this respect; hence find a large place in the diet of those of weakened digestive powers. Very ripe pulpy fruits may be added to such a list.
I will not, however, prolong these suggestions, for normally there is no occasion for the man or woman of advanced years to be on the invalid list. The pampering and coddling of people merely because they have reached a certain number of years is a fault too often committed by the children or others with whom they may have the ill fortune to live. It is often said that a man is as old as he feels, and the younger generation is prone to make him feel as old as he is, and then some.
On the whole I may say that there are no special dietetic laws for old age that do not apply to adult life in general. It is a question. always of eating foods that supply all the elements of nourishment that the body requires and of eating them in sufficient quantity to maintain the body in a wiry, muscular condition. Eat to keep thin as the years advance and your days upon this earth will be many.